Side bar cylinder lock



Dec. ll, 1951 R, c, spAlN 2,578,211

lSIDE BAR CYLINDER LOCK Filed July i6, 1948V Tkkg-2 22o 52 Tl ATTO R N EY Patented Dec. 11, 1951 SIDE BAR CYLINDER LOCK Roy Clifton Spain, Salem, Va., assignor to The Yale & Towne Manufacturing Company, Stamford, Conn., a corporation of Connecticut Application July 16, i948, Serial No. 38,969

(Cl. 'I0-366) 12 Claims. l

This invention relates to a lock, and more particularly to that type of lock in which a key plug moves relatively to a housing that frequently takes the form of a cylinder. More particularly, my invention relates to that type of lock of the particular class in which the movement of the key plug is controlled by a side bar that in turn is controlled by a series of tumblers.

In the usual side bar lock, a series of tumblers is manipulated by a key relatively to the key plug. If the tumblers are properly set, a, side bar that normally rests partially within a groove or the like in the cylinder and partially within the key plug, is moved entirely out of the groove in the cylinder and entirely within the area defined by the periphery of the key plug. Obviously, the key plug and the side bar are' then movable together to any position desired.

It is the object of my invention to contribute a lock of the particular class in which picking will be made extremely difficult. As a feature whereby this object of my invention -is attained, I make it possible for my key plug to Imove a limited degree relatively to the cylinder from what l term an initial central position. Upon application of picking torque to the key plug, this limited rotation of the key plug takes place, and the side bar is then held against movement into that zone defined by the periphery of the key plug.

As a further feature of this part of the invention,

surfaces are provided on the key plug for movement into holding relation to the side bar for holding the side bar in locking position so long as the key plug is moved away from said initial central position.

In my lock, I prefer to use a rotating plug and rotary tumblers that are set by the endwise movement of the key into the key plug. Those skilled in the art will appreciate that it is possible to arrange the mechanism so that other types of plugs, and tumblers otherwise mounted, may be utilized. In addition, my tumblers are so mounted in the key plug that their peripheries lie inwardly of that area encompassed by the periphery of the key plug. Still further, as a feature of my invention the tumbler peripheries are available to the side bar only within the extremely short angular zone defined by a groove in the key plug into which the side bar is adapted to move upon the setting of the tumblers. As a still further feature of this part of the invention, the side bar of my lock is formed as a simple cylindrical pin.

I have vthus outlined rather broadly the more important features of my invention in order that the detailed description thereof that follows may ill Iii

be better understood, and in order that my contribution to the art may be better appreciated. There are, of course, additional features of my invention that will be described hereinafter and which will form the subject of the claims appended hereto. Those skilled in the art will appreciate that the conception on which my disclosure is based may readily be utilized as a basis for the designing of other structures for carrying out the several purposes of my invention. It is important, therefore, that the claims to be granted me shall be of suicient breadth to prevent the appropriation of my invention by those skilled in the art.

Referring now to the drawings, Fig. 1 is a perspective view of the cylinder of my invention and a securing nut utilized in connection therewith. Fig. 2 is a view looking downwardly on the cylinder of Fig l. Figs. 3, 4, and 5 are sections taken along lines 3--3 of Fig. 2 showing the parts in different operating positions. Fig. 6 is a plan view of the key plug per se of my invention, while Fig. 7 is a perspective view of the side bar formed as a cylindrical pin. Fig. 8 is a section taken along lines 8 8 of Fig. 6.

Referring now more particularly to the drawings, the cylinder of my invention is designated by reference numeral I!) and within this cylinder I mount for rotation a key plug II, the cylinder It having a bore I2 therethrough in which the key plug I I is adapted to rotate. At this point it is important to indicate that frequently the cylinder will take the form of a handle equipped with a bore, or some other type of housing, all as those skilled in the art will fully appreciate. In the drawings the cylinder ID is of that type adapted to be secured in a housing by a nut Illa threaded thereon.

Key plug `I I, as best seen in Fig. 6, is formed with a head I3 at its forward end and with a keyway Id extending longitudinally therethrough. At its rear end the key plug-has a groove I5 into which ts a retainer IIS as best shown in Fig. 2, the retainer lying partially within the groove I5 and against theend surface i1 of the cylinder I0 so as to retain the key plug against endwise movement outwardly of the cylinder` I0.

Key plug II is further formed with a series of tumbler grooves I8 in each of which lies a tumbler I9. The tumbler grooves I8 are so formed as to present an end surface 2li against which presses one end of a spring 2 I. The other end of each of the springs 2l in the severaltumbler grooves I8 presses against a tumbler I9 mounted in each groove. The tumblersV I9 are adapted for rotation about a pin positioned longitudinally within the key plug i I, it being obvious that the tumblers will be urged in a counterclockwise direction about the pin '22 by the several springs 2l. Each tumbler is. equipped with a shoulder that is pressed against a stop surface 24 of each of the tumbler grooves is whereby to limit the counterclockwise rotation of the several tumblers. The shoulders 23 are contacted by a key K inserted in the keyway i@ as best shown in Fig. 4 whereby to rotate the tumblers against the force of the springs 2l. This rotation of the tumblers by the key K is intended to position the several gatings 25 of the tumblers in alignment with a deep release groove 2S formed longitudinally in the key plug I3.

The bore I2 oi the cylinder lil has formed therein a longitudinal locking groove 2l', and cooperable with the locking groove 2l of the cylinder and the release groove 25 of the key plug I I, is a cylindrical pin 28 forming the side bar of my lock. A spring 2S is staked into position at 30 relatively to the cylinder lll and bears at 3l against the pin 2S whereby to urge the said pin radially out of the locking groove 2l of the cylinder IEl and into the release groove 23 of the key plug II. Those skilled in the art will understand, of course, that when the several tumblers I 9 are properly set by the key K, the several gatings 25 of the tumblers will be in alignment with the release groove 2S of the key plug, so that the cylindrical pin 28 will move into the release groove 25 as well illustrated in Fig. Ll. Thereafter, the key plug together with the side bar will be rotatable either in a clockwise or counterclockwise direction.

The key plug Il, as best seen in G and 8, is formed, with relatively shallow grooves 32 at each side of the relatively deeper release groove 26. The shallow grooves 32 are of such size that they permit rotation of the key plug II relatively to the cylinder il? for some slight distance clockwise and counterclockwise from the central position or Figs. 3 and 4. This rotation is well illustrated in Fig. 5. It will be noted, however, from Fig. 5, that once the key plug is rotated as permitted by one of the shallow grooves 32, the deep release groove 2S is withdrawn from opposite the 23. Also, that sector of the key plug in which the tumblers are available to the side bar is moved away from opposite the side bar. Therefore, in Fig, 5, even if the several tumblers are aligned with their gatings opposite the pin 23, as is actually the case in Fig. 5, the locking pin will be held against movement into release position into the gatings. Therefore, it becomes impossible to pick the lock after the application oi picking torque thereto.

I believe that the construction of my invention will be made clearer by a simple review or one authorized key operation of the lock and also a description of what happens when an attempt is made to pick the lock. Let us first consider the locking mechanism in its initial position with the key out of the keyway If-s and the several tumblers held by the springs ZI in a fully rotated counterclockwisc position as shown in Fig. 3. In Fig. 3 the side bar or cylindrical pin 28 is held by the peripheries of the tumblers within the locking groove 2'! of the cylinder and against movement into the deep release groove If aproper key K is now inserted into the keyway Id, the tumblers will be rotated to the position oi Fig. to align their several gatings 25 with the deep release groove 25. The spring 29 will now press the pin 23 into the aligned gatings and into the deep release groove 2S. Key plug II will now be free for rotation. This is the action of the mechanism en properly key operated.

Let us new consider the parts of Fig. 3 in order to see lust what happens ir" an attempt is made to pick the lock. First, the lock picker must apply picking torque; that is, rotate the key plug to the limit permitted by the shallow grooves 32. 'Unless picking torque is applied to a key plug, is actually impossible to feel" the locking action. If picking torque is applied in a counterclockwise direction, the key plug will rotate to the position of 5.

With the parts in the position of -Fig, 5, even if the tumbleis are properly and fully picked as is actually illustrated in Fig. 5, it is impossible to rotate the key plug further in a counterclockwise direction. It becomes necessary, in order to permit the locking pin 2d to move to i c on in release groove to rotate the "ey plug back to the position` of Fig. 3. Gf course, while this is being done, the tumblers are released from whatever picking tool has been utilized, and the lock mechanism restored to its original locking condition.

T. believe that the rather considerable merit my invention and its operation will now be clear to those skilled in the art.

I now claim:

l. ln a lock of the class described, a cylinder, a key plug rotatable in a bore of said cylinder, a series or" tumblers carried by said key plug and movable relatively thereto by a key so as to be positioned in accordance with the bittings of said key, said tumblers having gatings adapted for alignment `when said tumblers are set by a properly pitted key, a side bar operatively positioned relatively to a groove formed in the here outlining sui'iace of said cylinder and also a groove of said key plug adapted for the full entry of said side bar therein to release said key plug for rotation, the tuinblers holding said side oar against full entry into said key plug groove until said gatings are in alignment with said key plug groove through t` e proper positioning of said tumblers, said key plug groove having a shallow extension at the side thereof to permit said key plug to rotate relatively to said cylinder and side bar as permitted by said shallow extension.

2. In a lock of the class described, a cylinder, a key plug movable in a bore of said cylinder, a series of tumblers carried by said key plug and movable relatively thereto by a key so as to be positioned in accordance with the bittings of said key, said tumblers having gatings adapted for alignment when said tumblers are set by a properly bitted key, a side bar operatively positioned relatively to a groove formed in the bore outlining surface of said cylinder and also groove of said key plug adapted for the full entry of said side t erein to release said l e for movement, the tumblers holding said side bar against full entry into said key plug groove until said gatings are in alignment through the proper positioning of said tuinblers, and said key plug groove having a shallow extension to permit said key plug to move relatively to said cylinder and side bar as permitted by said shallow extension.

Ina lock of the class described, a cylinder, a keyplug rotatable in a bore ol said cylinder, a series of tum lers carried by said key plug and movable relatively thereto by a key so as to be positioned in accordance with the bittings of saidl key, said tumblers having gatings adapted for alignment when said tumblers are set by a 'properly bitted key, a side bar operatively positioned relatively to a groove formed in the bore outlining surface of said cylinder and also a groove of said key plug adapted for the full entry of said side bar therein to release said key vplug for rotation, tumblers holding said side bar against full entry into said key plug groove until said gatings are in alignment with said key plug groove through the proper positioning of said tumblers, said key plug groove having a shallow extension at the side thereof to permit said key plug to rotate relatively to said cylinder and side bar as permitted by said shallow extension, the said shallow extension being not as deep as said tumbler gatings and thereby holding the side bar out of said tumbler gatings and iny said cylinder groove even if the tumbler gatings are aligned relatively to said shallow extension, whereby to require the return of said key plug to align its groove with said cylinder groove and the setting of said tumblers as a prerequisite to the release of said key plug for free rotation in said cylinder bore.

4. In a lock of the class described, a cylinder, a key plug rotatable in a bore of said cylinder, a series of tumblers carried by said key plug and movable relatively thereto by a key so as to be positioned in accordance with the bittings of said key, said tumblers moving in said key plug with their peripheral surfaces spaced at all times from the periphery of said key plug, said tumbler peripheries having gatings and said key plug having a groove formed in its periphery relatively to which said gatings are aligned when said tumblers are set by a properly bitted key, a side bar operatively positioned relatively to a locking groove formed in the bore outlining surface of said cylinder and also said key plug groove, the tumbler peripheries holding said side bar against full entry into said key plug groove until the tumbler gatings are placed in alignment with said groove whereby said side bar prevents free rotation of said key plug in said cylinder bore, said key plug groove having a shallow extension at the side thereof to permit said key plug to rotate relatively to said cylinder and side bar as permitted by said shallow extension, the said shallow extension not permitting the side bar to move into said tumblerv gatings and out of said cylinder groove even if tthe tumbler gatings are aligned relatively to said shallow extension, whereby to require the return of said key plug to align its groove with said cylinder groove and the setting of said tumblers as a prerequisite to the release of said key plug lfor free rotation in said cylinder bore.

5. In a lock of the class described, a cylinder, a key plug rotatable in a bore of said cylinder, a series of tumblers rotatably mounted in said key plug on an axis parallel to the axis of rotation of said key plug and movable relatively thereto by a key so as to be positioned in accordance with the bittings of said key, said tumblers having gatings and said key plug having a groove in its periphery parallel to the axis of rotation of said key plug and relatively to which said gatings are aligned when said tumblers are set by a properly bitted l key, a side bar operatively positioned relatively to a locking groove formed in the bore outlining surl face of said cylinder and also said key plug groove, the tumblers holding said side bar against full entry into said key plug groove until the tumbler gatings are placed in alignment with said key plug groove whereby said side bar prevents free rotation of said key plug in said cylinder bore, said key plug groove having a shallow extension at the side thereof to permit said key plug to rotate relatively to said cylinder and side bar as permitted by said shallow extension, the said shallow extension not permitting the side bar to move into said tumbler gatings and out of said cylinder groove even if the tumbler gatings are aligned relatively to said shallow extension, whereby to require the return of said key plug to align its groove with said cylinder groove and the setting of said tumblers as a prerequisite to the release of said key plug for free rotation in said cylinder bore.

6. In a lock of the class described, a cylinder, a key plug rotatable in a bore of said cylinder, a series of tumblers carried by said key plug and movable relatively thereto by a key so as to be positioned in accordance with the bittings of said key, said tumblers having gatings adapted for alignment when said tumblers are set by a properly bitted key, a side bar operatively positioned relatively to a groove formed in the bore outlining surface of said cylinder and also a groove of said key plug adapted for the full entry of said side bar therein to release said key plug for rotation, the tumblers holding said side bar against full entry into said key plug groove until said gatings are in alignment with said key plug groove through the proper positioning of said tumblers, said key plug groove having a shallow extension at each side thereof to permit said key plugto rotate relatively to said cylinder and side bar as permitted by said shallow extensions.

7. In a lock of the class described, a cylinder, a key plug rotatable in a bore of said cylinder, a series of tumblers carried by said key plug and movable relatively thereto by a key so as to be positioned in accordance with the bittings of said key, said tumblers having gatings adapted for alignment when said tumblers are set by a properly bitted key, a side bar operatively positioned relatively to a groove formed in the bore outlining surface of said cylinder and also a groove of said key plug adapted for the full entry of said side bar therein to release said key plug for rotation, the tumblers holding said side bar against full entry into said key plugI groove until said gatings are in alignment with said key plug groove through the proper positioning of said tumblers, said key plug groove having a shallow extension at each side thereof to permit said key plug to rotate relatively to said cylinder and side bar as permitted by said shallow extensions, the said shallow extensions being not as deep as said tumbler gatings whereby to hold the side bar out of said tumbler gatings and in said cylinder groove even if the tumbler gatings are aligned relatively to said shallow extensions, whereby to require the return of said key plug to align its groove with said cylinder groove and the setting of said tumblers as a prerequisite to the release of said key plug for free rotation in said cylinder bore.

8. In a lock of the class described, a cylinder, a key plug rotatable in a bore of said cylinder, a series of tumblers rotatably mounted in said key plug on an axis parallel to the axis of rotation of said key plug and movable relatively thereto by a key so as to be positioned in accordance with the bittings of said key, said tumblers having gatings and said key plug having a groove in its periphery parallel to the axis of rotation of said key plug and relatively to which said gatings are aligned when said tumblers are set by a properly bitted key, a side bar operatively positioned relatively to a locking groove formed in the bore outlining surface of said cylinder and also said key plug groove, the tumblers holding said side bar against full entry into said key plug groove until the tumbler gatings are placed in alignment with said key plug groove whereby said side bar prevents free rotation of said key plug in said cylinder bore, lsaid key plug groove having a shallow extension at the side thereof to permit said key plug to rotate relatively to said cylinder and side bar as permitted by said shallow extension, the said shallow extensions not permitting the side bar to move into said tumbler gatings and out of said cylinder groove even if the tumbler gatings are aligned relatively to said shallow extensions, whereby to require the return of said key plug to align its groove with said cylinder groove and the setting of said tumblers as a prerequisite to the release of said key plug for free rotation in said cylinder bore.

9. In a lock of the class described, a cylinder, a key plug rotatable in a bore of said cylinder, a series of tumblers carried by said key plug and movable relatively thereto by a key so as to be `positioned in accordance with the bittings of said key, said tumblers having gatings adapted for alignment when said tumblers are set by a properly bitted key, a side bar operatively positioned relatively to a groove formed in the bore outlin` ing surface of said cylinder and also a groove of said key plug adapted for the full entry of said side bar therein to release said key plug for rotation, la spring pressing said side bar toward said key vplug groove, the tumblers holding said side bar against full entry into said key plug groove until said gatings are in alignment with said key Vplug groove through the proper positioning of said movable relatively thereto by a key so as to be `positioned in accordance with the bittings of said key, said tumblers having gatings adapted for 'alignment when said tumblers are set by a prop erly bitted key, a cylindrical pin operatively positioned relatively to a longitudinal groove formed vin the bore outlining surface of said cylinder and alsoa longitudinal groove of Said key plug adapted forrthe full -entry of said side bar therein to release said key plug for rotation, a spring pressing said cylindrical pin toward said key plug groove,

the tumbler peripheries holding said side bar against full entry into said key plug groove until Vsaid gatings are in'alignment with said key plug groove `through the proper positioning of said tumblers, said key plug groove having a shallow 'extension atthe side thereof to permit said key plugto rotate relatively to said cylinder and 8 cylindrical pin as permitted by said shallow extension.

ll. In a lock of the class described, a cylinder, a key plug rotatable in a bore of said cylinder, a series of tumblers carried by said key plug and rotatable relatively thereto by a key so as to be positioned in accordance with the bittirigs of said key, said tumblers having gatings and said key plug having a groove in its periphery relatively to which said gatings are aligned when said tumblers are set by a properly bitted key, a side bar operatively positioned relatively to a locking groove formed in the bore outlining surface of said cylinder' and also said key plug groove, a spring pressing said. side bar toward said key plug groove, the tumblers holding said side bar against full entry into said key plug groove until the tumbler gatings are placed in alignment with said key plugl groove whereby said side bar prevents free rotation of said key plug in said cylinder bor-e, said key plug groove having a shallow extension at the side thereof to permit said key plug to rotate relatively to said cylinder and side bar as permitted by said shallow extension.

l2. In a lock of the class described, a cylinder, a key plug rotatable in a bore of said cylinder, a series of tumblers carried by said key plug and rotatable relatively thereto by a key so as to be positioned in accordance with the bittings of said said tumblers having gatings and said key having a longitudinal g-roove in its periphery relatively to which said gatings are aligned when tumblers are set by a properly bitted key, a locking pin operatively positioned relatively to a longitudinal locking groove formed in the bore outlining surface of said cylinder and also said key plug groove, a spring pressing said locking pin toward said key plug groove, the tumbler peripheries holding said locking pin against full entry into said key plug groove until the tumbler gatings are placed in alignment with said groove whereby said lockingpin prevents free rotation of said key plug in said cylinder bore, said key plug groove having a shallow extension at the side thereof to permit said key plug to rotate relatively to said cylinder and locking pin as permitted by said shallow extension, the said shallow extension being not as deep as said tumbler gatings whereby to hold the locking pin out of said tumbler gatings and in said cylinder groove even if the tumbler gat-ings are aligned relatively to said shallow extension, whereby to require the return cf said key plug to align its groove with said cylinder groove and the setting of said tumblers as a prerequisite to the Yrelease of said key plug for free rotation in said cylinder bore.

ROY CLIFTON SPAIN.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 199,0e8 Folter Jan. 8, 1878 2,070,233 Liss Feb. 9, 1937 2,182,588 Jacobi Dec. 5, 1939 

